Manual Pages for UNIX Operating System command usage for man ldi_ev_notify

Kernel Functions for Drivers                    ldi_ev_notify(9F)



NAME
     ldi_ev_notify - propagate notification  of  a  state  change
     event

SYNOPSIS
     #include 

     int ldi_ev_notify(dev_info_t *dip, minor_t minor, int spec_type,
          ldi_ev_cookie_t cookie, void *ev_data);


INTERFACE LEVEL
     Solaris DDI specific (Solaris DDI)

PARAMETERS
     dev_info_t *dip

         The devinfo node of the layered consumer  exporting  the
         minor device.


     minor_t minor

         The minor number of the exported minor device.


     int spec_type

         The type of minor device (S_IFCHR or S_IFBLK).


     ldi_ev_cookie_t cookie

         An opaque event cookie for the event type returned by  a
         previous call to ldi_ev_get_cookie(9F).


     void *ev_data

         Event specific data.


DESCRIPTION
     The ldi_ev_notify() function  propagates  an  event  up  the
     software stack. It may result in two actions:

         o    Invocation of LDI callback handlers  registered  by
              layered drivers up the software stack.

         o    Device contract events generated on minors exported
              to userland.




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Kernel Functions for Drivers                    ldi_ev_notify(9F)



     The event propagated up the software stack may be  different
     than  the  event  received  by  the  layered driver invoking
     ldi_ev_notify(). For example, a volume manager  may  receive
     an  "offline" event on one of it's LDI opened disks, but may
     choose to propagate a "degraded" event on minors it  exports
     to  userland  (since  it  may have more than one copy of the
     data). The event cookie argument to ldi_ev_notify()  may  be
     different  from  the event cookie currently possessed by the
     layered driver. If that is the case, the layered driver must
     generate     another     event     cookie    via    a    new
     ldi_ev_get_cookie(9F) call.


     Theldi_ev_* interfaces are designed to ensure that a "final-
     ize"  call  is generated for layered driver consumers at the
     earliest point where an LDI_EV_FAILURE is detected. If  this
     happens  inside  the LDI event framework, then the framework
     will  invoke  finalize.  In  the  event  a  layered   driver
     detects/generates an LDI_EV_FAILURE, then the layered driver
     must invoke ldi_ev_finalize(). The following is  an  example
     of a layered driver invoking ldi_ev_finalize() for the "foo"
     event:

       static int
        widget_notify(ldi_handle_t lh, ldi_ev_cookie_t foo_cookie, void *arg,
            void *ev_data)
        {

                ASSERT(strcmp(ldi_ev_get_type(foo_cookie), LDI_EV_FOO) == 0);

                /* Map imported minors to exported minor */
                widget_map(lh, &minor, &spec_type);

                /*
                 * Call ldi_ev_notify() to propagate events to our consumers.
                 * This *must* happen before we check if widget should block
                 * foo
                 */
                 if (ldi_ev_notify(dip, minor, spec_type, foo_cookie, ev_data)
                     != LDI_EV_SUCCESS)
                         return (LDI_EV_FAILURE);

                /*
                 * Next, check if we can allow the foo event
                 */
                 if (widget_release(lh, LDI_EV_FOO) == WIDGET_SUCCESS) {
                         return (LDI_EV_SUCCESS)
                 }

                 /*
                  * We cannot permit the foo event. The first layer that detects
                  * failure i.e. us, must generate finalize events for *our*



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Kernel Functions for Drivers                    ldi_ev_notify(9F)



                  * consumers
                  */
                 ldi_ev_finalize(dip, minor, spec_type, LDI_EV_FAILURE,
                     foo_cookie, ev_data);

                 return (LDI_EV_FAILURE);
       }


RETURN VALUES
     The return values for this function are:

     LDI_EV_SUCCESS

         Consumers up the software stack permit state change.


     LDI_EV_FAILURE

         Consumers are blocking the state change.


CONTEXT
     This function can be called from  user  and  kernel  context
     only.

SEE ALSO
     ldi_ev_get_cookie(9F),        ldi_ev_register_callbacks(9F),
     ldi_ev_remove_callbacks(9F)


























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